Apparatus and techniques for freezing and thawing of agricultural produce

ABSTRACT

Apparatus for preserving fresh cut or uncut agricultural produce including a chamber operative to remove moisture from the fresh cut or uncut agricultural produce in an amount equal to between 5%-20% of the weight of the fresh cut or uncut agricultural produce and at least one freezing device operative to freeze the fresh cut or uncut agricultural produce.

REFERENCE TO CO-PENDING APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/600,488, filed Nov. 15, 2006, entitled “APPARATUS AND TECHNIQUES FORFREEZING AND THAWING OF AGRICULTURAL PRODUCE”, the contents of which areincorporated by reference.

FIELD OF THE INVENTION

The present invention relates to system, apparatus and techniques forfreezing and thawing of agricultural produce.

BACKGROUND OF THE INVENTION

The following published documents are believed to represent the currentstate of the art and the contents thereof are hereby incorporated byreference: U.S. Pat. Nos. 5,595,775; 5,256,438; 5,135,122; 5,020,237;4,647,469; 4,551,384; 4,418,082; 4,390,550; 4,356,195; 4,350,711 and4,332,824;

U.K. Published Patent Application No. 2005983A;

“Drying, shrinkage and rehydration characteristics of Kiwifruits duringhot air and microwave drying”, M. Maskan, Journal of Food Engineering,48, 177-182, (2001);

“Kinetics of moisture transfer during air drying of blanched and/orosmotically dehydrated mango”, A. Nieto, M. A. Castro and S. M Alzamora,Journal of Food Engineering, 50, 175-185, (2001);

“Analysis of shrinkage phenomenon of whole sweet cherry fruits (Prunusavium) during convective dehydration with very simple models”, M. R.Ochoa, A. G. Kessler, B. N. Pirone, C. A Marquez and A. De Michelis,Journal of Food Engineering, (2006); and

“Drying kinetics of pomegranate arils”, A. R. P. Kingsley and D. B.Singh, Journal of Food Engineering, (2006).

SUMMARY OF THE INVENTION

The present invention seeks to provide improved apparatus and techniquesfor freezing and thawing of agricultural produce which maintainsfresh-like qualities in the frozen produce when thawed.

There is thus provided in accordance with a preferred embodiment of thepresent invention a method for preserving uncut fresh agriculturalproduce including manually handling the uncut fresh agriculturalproduce, thereafter, removing moisture from the uncut fresh agriculturalproduce in an amount equal to between 5%-20% of the weight of the uncutfresh agricultural produce at a rate which does not exceed approximately30×10⁻⁶ kg moisture/sec per area unit of the produce in meter² andthereafter, freezing the uncut fresh agricultural produce.

Preferably, the manually handling is effective to generally eliminatedamage to an outer peel of the uncut fresh agricultural produce.

There is also provided in accordance with another preferred embodimentof the present invention a method for preserving uncut freshagricultural produce including non-manually handling the uncut freshagricultural produce, thereafter, removing moisture from the uncut freshagricultural produce in an amount equal to between 5%-20% of the weightof the uncut fresh agricultural produce at a rate which does not exceedapproximately 60×10⁻⁶ kg moisture/sec per area unit of the produce inmeter²; and thereafter, freezing the uncut fresh agricultural produce.

There is further provided in accordance with yet another preferredembodiment of the present invention a method for preserving fresh cutagricultural produce including removing moisture from the fresh cutagricultural produce in an amount equal to between 5%-20% of the weightof the fresh cut agricultural produce at a rate which does not exceedapproximately 300×10⁻⁶ kg moisture/sec per area unit of the produce inmeter² and thereafter, freezing the fresh cut agricultural produce.

There is even further provided in accordance with still anotherpreferred embodiment of the present invention a method of storingagricultural produce including removing moisture from the agriculturalproduce in an amount equal to between 5%-20% of the weight of theagricultural produce, thereafter, freezing the agricultural produce andthereafter, adding liquid to the agricultural produce and defrosting theagricultural produce in the presence of the liquid.

There is yet further provided in accordance with yet another preferredembodiment of the present invention a method for storing agriculturalproduce including removing moisture from the agricultural produce in anamount equal to between 5%-20% of the weight of the agriculturalproduce, thereafter, freezing the agricultural produce and storing it ina container for storing frozen agricultural produce and having acontainer opening, sealing the opening of the container, storing thecontainer containing the agricultural produce under freezing conditions,unsealing the opening of the container, supplying a liquid to theagricultural produce in the container, defrosting the agriculturalproduce in the container in the presence of the liquid, removablyattaching an apertured cap to the container and pouring out the liquidfrom the container through the apertured cap, thereby permitting theliquid, but not the produce, to pass out of the container.

Preferably, the removing moisture includes removing moisture in anamount equal to approximately 10%-14% of the weight of the agriculturalproduce. More preferably, the removing moisture includes removingmoisture in an amount equal to approximately 12% of the weight of theagricultural produce.

Preferably, the removing moisture includes transporting the agriculturalproduce through a moisture removal chamber. Additionally, the removingmoisture includes transporting the agricultural produce through acontrolled temperature chamber. Additionally or alternatively, theremoving moisture includes transporting the agricultural produce througha controlled air flow chamber. More preferably, the removing moistureincludes transporting the agricultural produce through a controlledtemperature and air flow chamber.

Alternatively, the removing moisture includes transporting theagricultural produce through a convection drying chamber. Alternatively,the removing moisture includes transporting the agricultural producethrough at least one of a microwave chamber, an infrared chamber, aconvection chamber, a chamber having fluidized bed technology and achamber having vacuum drying technology.

Preferably, the method also includes, prior to the freezing, pre-coolingthe agricultural produce to a temperature between 0° C. and 5° C.

Preferably, the freezing includes freezing the agricultural produce to atemperature between −40° C. and −35° C. Additionally or alternatively,the freezing includes quick freezing the agricultural produce.Alternatively or additionally, the freezing includes freezing theagricultural produce by employing IQF freezing technology.

Preferably, the method also includes, following the freezing, addingliquid to the agricultural produce and defrosting the agriculturalproduce in the presence of the liquid.

Preferably, the method for storing includes storing different types ofthe agricultural produce mixed together.

Preferably, the defrosting includes defrosting the agricultural produceat room temperature. Additionally, the defrosting the agriculturalproduce at room temperature includes defrosting the agricultural produceat room temperature for a duration of approximately 3 to 5 minutes.Alternatively, the defrosting includes defrosting the agriculturalproduce in a microwave oven. Additionally, the defrosting theagricultural produce in a microwave oven includes defrosting theagricultural produce in a microwave oven for a duration of approximately15 to 30 seconds.

There is also provided in accordance with still another preferredembodiment of the present invention apparatus for preserving manuallyhandled uncut fresh agricultural produce including a chamber operativeto remove moisture from the manually handled uncut fresh agriculturalproduce in an amount equal to between 5%-20% of the weight of themanually handled uncut fresh agricultural produce at a rate which doesnot exceed approximately 30×10⁻⁶ kg moisture/sec per area unit of theproduce in meter² and at least one freezing device operative to freezethe manually handled uncut fresh agricultural produce.

There is further provided in accordance with another preferredembodiment of the present invention apparatus for preservingnon-manually handled uncut fresh agricultural produce including achamber operative to remove moisture from the non-manually handled uncutfresh agricultural produce in an amount equal to between 5%-20% of theweight of the non-manually handled uncut fresh agricultural produce at arate which does not exceed approximately 60×10⁻⁶ kg moisture/sec perarea unit of the produce in meter² and at least one freezing deviceoperative to freeze the non-manually handled uncut fresh agriculturalproduce.

There is even further provided in accordance with yet another preferredembodiment of the present invention apparatus for preserving fresh cutagricultural produce including a chamber operative to remove moisturefrom the fresh cut agricultural produce in an amount equal to between5%-20% of the weight of the fresh cut agricultural produce at a ratewhich does not exceed approximately 300×10⁻⁶ kg moisture/sec per areaunit of the produce in meter² and at least one freezing device operativeto freeze the fresh cut agricultural produce.

Preferably, the chamber is operative to remove moisture in an amountequal to approximately 10%-14% of the weight of the agriculturalproduce. More preferably, the chamber is operative to remove moisture inan amount equal to approximately 12% of the weight of the agriculturalproduce.

Preferably, the chamber is a controlled temperature and air flowchamber. Alternatively, the chamber is a controlled air flow chamber.Alternatively, the chamber is a controlled temperature chamber.

Preferably, the chamber is a convection drying chamber. Alternatively,the chamber is at least one of a microwave chamber, an infrared chamber,a convection chamber, a chamber having fluidized bed technology and achamber having vacuum drying technology.

Preferably, the apparatus also includes a cooling device operative topre-cool the agricultural produce prior to the freezing thereof, to atemperature between 0° C. and 5° C.

Preferably, the at least one freezing device is operative to freeze theagricultural produce to a temperature between −40° C. and −35° C.Additionally or alternatively, the at least one freezing device isoperative to quick freeze the agricultural produce. Alternatively oradditionally, the at least one freezing device employs IQF freezingtechnology.

There is still further provided in accordance with still anotherpreferred embodiment of the present invention apparatus for storingagricultural produce including a container for storing the frozenagricultural produce and having a container opening, a seal formed overthe opening of the container, a cap removably attached to the containerand disposed over the seal, the cap being apertured to permit liquid,but not the produce, to pass therethrough and out of the container.

Preferably, the container has indicated thereon a line indicating adesired level to which the liquid should be added to the container priorto defrosting.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description, taken in conjunction with thedrawings in which:

FIGS. 1A, 1B and 1C are simplified illustrations of apparatus andtechniques for preserving agricultural produce in accordance with threealternative embodiments of the present invention; and

FIGS. 2A, 2B and 2C are simplified illustrations of apparatus andtechniques for freezing, packaging, storing, defrosting and utilizingagricultural produce in accordance with a preferred embodiment of thepresent invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference is now made to FIGS. 1A, 1B and 1C, which are simplifiedillustrations of apparatus and techniques for preserving agriculturalproduce in accordance with three alternative embodiments of the presentinvention.

Turning to FIG. 1A, there is seen a method and apparatus for preservinguncut fresh agricultural produce including manually handling the uncutfresh agricultural produce, thereafter, removing moisture from the uncutfresh agricultural produce in an amount equal to between 5%-20% of theweight of the uncut fresh agricultural produce at a rate which does notexceed approximately 30×10⁻⁶ kg moisture/sec per area unit of produce inmeter² and thereafter, freezing the uncut fresh agricultural produce.

In the illustrated method, pomegranate arils 100 are separated fromfresh pomegranates by hand, as indicated at reference numeral 102, andplaced on a conveyor 104 in a manner designed so as to generallyeliminate or minimize damage to the outer peel 106 thereof.

The conveyor 104 transports the pomegranate ails 100 through a moistureremoval chamber 108, preferably a controlled temperature and air flowchamber, in order to remove moisture therefrom, in an amount preferablyequal to between approximately 5%-20%, and more preferably equal tobetween approximately 10%-14%, of the weight of the pomegranate ails100, at a rate which does not exceed approximately 30×10⁻⁶ kgmoisture/sec per area unit of produce in meter². In the illustratedexemplary embodiment, moisture removal takes approximately 1.5 hours andpreferably results in removal of moisture equal to approximately 12% ofthe weight of the pomegranate arils 100.

It is appreciated that moisture removal chamber 108 may be any suitablecontrolled drying chamber utilizing any suitable drying technology, suchas microwave, infra-red, convection, fluidized bed or vacuum dryingtechnologies and various combinations thereof. Convection drying ispresently preferred.

Following moisture removal thereof as described hereinabove, thepomegranate ails 100 are preferably pre-cooled in a cooler 110 to atemperature between 0° C.-5° C. and are then preferably quick frozen,preferably to a temperature between −40° C. and −35° C., preferably in afreezer 112 employing IQF (individual quick frozen) freezing technology.Alternatively, the pre-cooling step may be obviated.

Turning to FIG. 1B, there is seen a method and apparatus for preservinguncut fresh agricultural produce including non-manually handling theuncut fresh agricultural produce, thereafter, removing moisture from theuncut fresh agricultural produce in an amount equal to between 5%-20% ofthe weight of the uncut fresh agricultural produce at a rate which doesnot exceed approximately 60×10⁻⁶ kg moisture/sec per unit area ofproduce in meter² and thereafter, freezing the uncut fresh agriculturalproduce.

In the illustrated method, pomegranate arils 120 are separated fromfresh pomegranates by use of a machine 122, such as, for example, thetype described in published PCT application No. WO/2004/071249. Arils120 are placed on a conveyor 124. The conveyor 124 transports thepomegranate arils 120 through a moisture removal chamber 128, preferablya controlled temperature and air flow chamber, in order to removemoisture therefrom, in an amount preferably equal to betweenapproximately 5%-20%, and more preferably between approximately 10%-14%,of the weight of the pomegranate arils 120, at a rate which does notexceed approximately 60×10⁻⁶ kg moisture/sec per area unit of produce inmeter². In the illustrated exemplary embodiment, moisture removal takesapproximately 50 minutes and preferably results in removal of moistureequal to approximately 12% of the weight of pomegranate ails 120.

It is appreciated that moisture removal chamber 128 may be any suitablecontrolled drying chamber utilizing any suitable drying technology, suchas microwave, infra-red, convection, fluidized bed or vacuum dryingtechnologies and various combinations thereof. Convection drying ispresently preferred.

Following moisture removal thereof as described hereinabove, thepomegranate arils 120 are preferably pre-cooled in a cooler 130 to atemperature between 0° C.-5° C. and are then preferably quick frozen,preferably to a temperature between −40° C. and −35° C., preferably in afreezer 132 employing IQF freezing technology. Alternatively, thepre-cooling step may be obviated.

Turning to FIG. 1C, there is seen a method and apparatus for preservingfresh cut agricultural produce including manually handling the fresh cutagricultural produce, thereafter, removing moisture from the fresh cutagricultural produce in an amount equal to between 5%-20% of the weightof the fresh cut agricultural produce at a rate which does not exceedapproximately 300×10⁻⁶ kg moisture/sec per area unit of produce inmeter² and thereafter, freezing the fresh cut agricultural produce.

In the illustrated method, fresh cut pieces 140 of mango are preparedfrom fresh mangos by hand, as indicated at reference numeral 142.Alternatively, fresh cut pieces 140 of mango may be non-manuallyprepared. Fresh cut pieces 140 of mango are placed on a conveyor 144.The conveyor 144 transports the fresh cut pieces 140 of mango through amoisture removal chamber 148, preferably a controlled temperature andair flow chamber, in order to remove moisture therefrom, in an amountpreferably equal to between approximately 5%-20%, and more preferablybetween approximately 10%-14%, of the weight of the fresh cut pieces 140of mango, at a rate which does not exceed approximately 300×10⁻⁶ kgmoisture/sec per area unit of produce in meter². In the illustratedexemplary embodiment, moisture removal takes approximately 40 minutesand preferably results in removal of moisture equal to approximately 12%of the weight of fresh cut pieces 140 of mango.

It is appreciated that moisture removal chamber may be any suitablecontrolled drying chamber utilizing any suitable drying technology, suchas microwave, infra-red, convection, fluidized bed or vacuum dryingtechnologies and various combinations thereof. Convection drying ispresently preferred.

Following moisture removal thereof as described hereinabove, the freshcut pieces 140 of mango are preferably pre-cooled in a cooler 150 to atemperature between 0° C.-5° C. and are then preferably quick frozen,preferably to a temperature between −40° C. and −35° C., preferably in afreezer 152 employing IQF freezing technology. Alternatively, thepre-cooling step may be obviated.

Although the invention has been described hereinabove with respect topomegranate arils and fresh cut pieces of mango, it is appreciated thatit is applicable to a great many types of agricultural produce. Data forvarious types of uncut produce appears in Table 1 hereinbelow and datafor various types of fresh cut produce appears in Table 2 hereinbelow.It is seen that for each type of produce various drying rates andcorresponding quality metrics, such as turgor, general taste, drip lossand dried tissue layer as a percentage by weight of produce weight, areindicated.

TABLE 1 UNCUT PRODUCE Parameter Drying Drying rate per Turgor on 0-5General taste Drip Temp. unit area of product Dehydration, scale (5 ison 0-5 scale loss, Type (° C.) (kg m⁻² s⁻¹) × 10⁻⁶ % best) (5 is best) %Cherry 45 16 5 4 3.9 6.1 (Sweet) 45 16 8 4.4 4.4 4.3 Manually 45 16 124.7 4.8 0.2 handled 45 16 18 4.2 3.4 0.1 50 27 12 4.7 4.7 0.8 60 59 123.9 3.5 2.2 Control 0 3.3 3.1 7.3 Pomegranate 40 7 12 4.5 4.6 0.4(Wonderful) 50 30 6 2.9 3.2 6.2 Manually 50 30 8 3.7 3.6 4.2 handled 5030 10 4.1 3.9 3.9 50 30 12 4.5 4.6 1.2 50 30 14 4.5 4.6 0.6 50 30 16 3.73.9 0.4 60 59 12 4.2 4.2 1.8 70 116 12 4 4 2.5 Control 0 2.3 2.6 13.2Pomegranate 40 5 12 4.4 4.3 0.6 (Hershkovich) 45 11 12 4.4 4.3 0.7Manually 50 19 12 4.3 4.3 1.1 handled 60 77 12 4.1 4 1.6 70 121 12 3.73.8 3.2 Control 0 2.2 2.5 12.3 Pomegranate 25 2 12 4.2 3.8 0.6 (Rosh- 4010 12 4.2 3.8 0.6 Hapered) 43 17 12 4 3.7 1.2 Manually 45 26 12 3.6 3.23.2 handled 50 46 12 3.2 2.8 6.2 70 89 12 3 2.5 7.4 Control 0 1.7 2.118,7 Pomegranate 40 16 12 4.3 4.1 0.8 (105) 45 27 12 4.3 4.1 1.2 Non- 5045 12 4.3 4.1 1.2 Manually Control 0 2.3 2.3 14.6 handled Blueberry 4511 12 4.8 4.8 0 60 32 12 4.7 4.1 0.2 Control 0 4.1 3.9 0.7

Based on the experimental results of the inventors, the optimalparameters and corresponding experimental results for each of thevarious types of produce of Table 1 are shown in bold in Table 1.

As seen in Table 1, for Sweet Cherries, the optimal parameters andcorresponding experimental results are generally as follows:

Drying Temperature: 45° C.

Drying Rate per Unit Area: 16 kg/(sec*m²*10⁶)

Dehydration Percentage: 12%

Turgor: 4.7 (on a scale of 0-5 with 5 being best)

General Taste Score: 4.8 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 0.2%

As seen in Table 1, two sets of optimal parameters were found. Theoptimal parameters and corresponding experimental results forPomegranate arils (Wonderful variety) are respectively as follows:

Drying Temperature: 50 and 50° C.

Drying Rate per Unit Area: 30 and 30 kg/(sec*m²*10⁶)

Dehydration Percentage: 12% and 14%

Turgor: 4.5 and 4.5 (on a scale of 0-5 with 5 being best)

General Taste Score: 4.6 and 4.6 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 1.2% and 0.6%

As seen in Table 1, the optimal parameters and correspondingexperimental results for Pomegranate arils (Hershkovitz variety) are asfollows:

Drying Temperature: 45° C.

Drying Rate per Unit Area: 11 kg/(sec*m²*10⁶)

Dehydration Percentage: 12%

Turgor: 4.4 (on a scale of 0-5 with 5 being best)

General Taste Score: 4.3 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 0.7%

As seen in Table 1, the optimal parameters and correspondingexperimental results for Pomegranate arils (Rosh-Hapered variety) are asfollows:

Drying Temperature: 40° C.

Drying Rate per Unit Area: 10 kg/(sec*m²*10⁶)

Dehydration Percentage: 12%

Turgor: 4.2 (on a scale of 0-5 with 5 being best)

General Taste Score: 3.8 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 0.6%

As seen in Table 1, two sets of optimal parameters were found. Theoptimal parameters and corresponding experimental results forPomegranate arils (105 variety) are respectively as follows:

Drying Temperature: 45 and 50° C.

Drying Rate per Unit Area: 27 and 45 kg/(sec*m²*10⁶)

Dehydration Percentage: 12% and 12%

Turgor: 4.3 and 4.3 (on a scale of 0-5 with 5 being best)

General Taste Score: 4.1 and 4.1 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 1.2% and 1.2%

As seen in Table 1, the optimal parameters and correspondingexperimental results for Blueberries are as follows:

Drying Temperature: 45° C.

Drying Rate per Unit Area: 11 kg/(sec*m²*10⁶)

Dehydration Percentage: 12%

Turgor: 4.8 (on a scale of 0-5 with 5 being best)

General Taste Score: 4.8 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 0%

TABLE 2 FRESH CUT Parameter Drying Drying rate per Turgor on 0-5 Generaltaste Drip Dried Temp. unit area of product Dehydration, scale (5 is on0-5 scale loss, tissue Type (° C.) (kg m⁻² s⁻¹) × 10⁻⁶ % best) (5 isbest) % layer, % Mango 27 87 14 4.4 4.5 0.4 0.5 33 146 14 4.4 4.5 0.40.7 40 195 5 3.5 3.2 4.8 0.3 40 195 10 4.1 3.6 2.3 0.7 40 195 14 4.4 4.50.4 0.7 40 195 25 3.8 3.7 0.2 4.2 50 315 14 4.4 4.2 1.6 3.2 60 378 14 43.8 2.1 7.4 Control 0 3.4 3.2 8.3 0 Kiwi 24 75 16 3.8 3.6 1.8 0.1 39 23316 3.8 3.6 2 0.1 48 280 5 2.9 2.7 7.9 0 48 280 10 3.4 2.9 5.7 0.1 48 28016 3.8 3.4 2.2 0.3 48 280 22 2.7 3.1 0.6 2.3 55 395 16 3.6 3.4 2.2 0.760 421 16 3.6 3.2 2.8 1.2 70 451 16 3.2 3.2 3.1 2.6 Control 0 2.6 2.414.6 0 Melon 25 101 16 4.8 4.7 0.4 0 (Charante) 39 224 5 3.8 3.9 3.7 039 224 10 4.2 4.3 1.8 0.2 39 224 16 4.7 4.7 0.4 0.4 39 224 25 4.1 3.60.3 5.4 49 302 16 4.5 4.5 0.5 2.3 70 370 16 3.9 3.8 0.5 4.7 Control 03.5 3.4 6.3 0 Pineapple 25 125 18 4.4 4.7 1.3 0.2 43 208 5 3.9 3.9 5.10.4 43 208 12 4.4 4.7 1.7 0.5 43 208 18 4.3 4.5 1.6 0.6 43 208 25 3.83.8 1.1 3.8 55 339 18 4.3 4.5 1.6 0.6 60 489 18 4.2 4.2 2 3.6 70 731 184.2 4.2 2 5.3 Control 0 3.6 3.6 7.8 0 Bell 40 72 5 4 3.7 2.7 0 Pepper 4072 12 4.4 4.3 0.4 0 40 72 18 3.9 3.8 0.2 0 Control 0 3.6 3.4 3.3 0

The optimal parameters and corresponding experimental results for eachof the various types of produce, based on the experimental results ofthe inventors, are shown in bold in Table 2.

As seen in Table 2, for Mangos, the optimal parameters and correspondingexperimental results are generally as follows:

Drying Temperature: 40° C.

Drying Rate per Unit Area: 195 kg/(sec*m²*10⁶)

Dehydration Percentage: 14%

Turgor: 4.4 (on a scale of 0-5 with 5 being best)

General Taste Score: 4.5 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 0.4%

Dried Tissue Layer Percentage: 0.7%

The optimal parameters and corresponding experimental results for Kiwiare as follows:

Drying Temperature: 39° C.

Drying Rate per Unit Area: 233 kg/(sec*m²*10⁶)

Dehydration Percentage: 16%

Turgor: 3.8 (on a scale of 0-5 with 5 being best)

General Taste Score: 3.6 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 2%

Dried Tissue Layer Percentage: 0.1%

The optimal parameters and corresponding experimental results for Melon(Charante variety) are as follows:

Drying Temperature: 39° C.

Drying Rate per Unit Area: 224 kg/(sec*m²*10⁶)

Dehydration Percentage: 16%

Turgor: 4.7 (on a scale of 0-5 with 5 being best)

General Taste Score: 4.7 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 0.4%

Dried Tissue Layer Percentage: 0.4%

The optimal parameters and corresponding experimental results forPineapple are as follows:

Drying Temperature: 43° C.

Drying Rate per Unit Area: 208 kg/(sec* m²*10⁶)

Dehydration Percentage: 12%

Turgor: 4.4 (on a scale of 0-5 with 5 being best)

General Taste Score: 4.7 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 1.7%

Dried Tissue Layer Percentage: 0.5%

The optimal parameters and corresponding experimental results for BellPeppers are as follows:

Drying Temperature: 40° C.

Drying Rate per Unit Area: 72 kg/(sec* m²*10⁶)

Dehydration Percentage: 12%

Turgor: 4.4 (on a scale of 0-5 with 5 being best)

General Taste Score: 4.3 (on a scale of 0-5 with 5 being best)

Drip Loss Percentage: 0.4%

Dried Tissue Layer Percentage: 0%

It is appreciated that the optimal rate of moisture removal and themaximum moisture removal rates described hereinabove are a function ofthe condition of the agricultural produce prior to moisture removal.Thus, for example, the pieces 140 of mango described in the embodimentof FIG. 1C do not include an outer peel or rind which could affect themoisture removal process, while the arils 100 of FIG. 1A generally doinclude an outer peel 106. In the embodiment shown in FIG. 1B, the outerpeel of arils 120 may have been damaged by the separation process bymachine 122. It is appreciated that while the embodiment of FIG. 1Bdescribes agricultural produce where the outer peel may have beendamaged by non-manual handling thereof, the optimal rate of moistureremoval and the maximum moisture removal rates described therein mayalso apply to agricultural produce where the outer peel may have beendamaged by manual handling thereof. It is appreciated that while theembodiment of FIG. 1C describes fresh cut agricultural produce, theoptimal rate of moisture removal and the maximum moisture removal ratesdescribed therein may also apply to uncut agricultural produce where theouter peel may have been removed.

Reference is now made to FIGS. 2A, 2B and 2C, which are simplifiedillustrations of apparatus and techniques for freezing, packaging,storing, defrosting and utilizing agricultural produce in accordancewith a preferred embodiment of the present invention.

As seen in FIG. 2A, agricultural produce, typically including at leastone or both of uncut fresh produce and fresh cut produce, is preferablyfrozen in accordance with the present invention, preferably usingtechniques of the type described hereinabove with reference to FIGS.1A-1C. These techniques preferably all include removing moisture fromthe fresh agricultural produce in an amount equal to between 5%-20% ofthe weight of the fresh agricultural produce at a rate which does notexceed predetermined thresholds depending on the nature of the produceas described hereinabove with reference to FIGS. 1A-1C and thereafter,freezing the fresh agricultural produce.

The frozen agricultural produce, preferably in bite-size pieces, ispreferably mixed together in any suitable manner, and packaged inaccordance with a preferred embodiment of the invention.

In the illustrated embodiment, uncut pomegranate arils 210, cherries 212and fresh cut pieces 214 of mango are each frozen in accordance with thepresent invention and optionally supplied to a mixer 216. A conveyor 218transports the mixed frozen produce 220 to a packaging station 222 whichincludes a filler 224, which fills cup-like packages 226 with the mixedfrozen produce 220, a sealer 228, which applies a seal 230 onto a rim232 of each package 226 and a capper 234, which attaches a removable,apertured cap 236 over seal 230 onto each package 226. The filledpackages 240 may be shipped to retail outlets for retail distribution.It is appreciated that the freezing of various items of produce inaccordance with a preferred embodiment of the invention need not takeplace at the same location and need not take place at the location wherethe subsequent packaging takes place.

As will be described in greater detail hereinbelow, it is a particularfeature of the present invention that produce, frozen in accordance witha preferred embodiment of the present invention, is packaged in apackage which enables water or other liquid to be added thereto topromote quick and homogeneous defrosting thereof. As seen particularlyin FIG. 2B, when a consumer wishes to consume the frozen produce, heremoves a filled package 240 from a freezer 242 as indicated byreference numeral 250, removes the cap 236, as indicated by referencenumeral 252, removes the seal 230, as indicated by reference numeral254, and adds water as indicated by reference numeral 256, preferably upto a line 260 indicated on the package 240. Preferably, after addingwater, the consumer reattaches the cap 236 to the rim 232 of package240, as indicated by reference numeral 258. After the package 240 isleft at room temperature for at least a predetermined short time,typically 3-5 minutes, the produce in package 240 is fully defrosted.Alternatively, the package 240 may be defrosted in a microwave oven athigh power for approximately 15-30 seconds. Following defrosting, theconsumer pours out excess liquid through apertured cap 236, as indicatedby reference numeral 260. The cap 236 may then be removed and discardedand the produce may be eaten.

It is a particular feature of the present invention that due toextremely low drip loss, the produce in the mixture is not discoloredand the juices of the produce are not lost when pouring out the excessliquid, which is generally clear.

It is appreciated that any other suitable technique for defrosting thefrozen produce, following addition thereto of water, may be employed.One example is the use of a microwave oven.

It is appreciated by persons skilled in the art that the presentinvention is not limited by what has been particularly shown anddescribed hereinabove. Rather the scope of the present inventionincludes both combinations and subcombinations of various featuresdescribed hereinabove as well as variations and modifications theretowhich would occur to a person of skill in the art upon reading the abovedescription and which are not in the prior art.

1. A method for preserving uncut fresh agricultural produce comprising:manually handling said uncut fresh agricultural produce; thereafter,removing moisture from said uncut fresh agricultural produce in anamount equal to between 5%-20% of the weight of said uncut freshagricultural produce at a rate which does not exceed approximately30×10⁻⁶ kg moisture/sec per area unit of said produce in meter²; andthereafter, freezing said uncut fresh agricultural produce.
 2. A methodaccording to claim 1 and wherein said removing moisture comprisesremoving moisture in an amount equal to approximately 10%-14% of saidweight of said agricultural produce.
 3. A method according to claim 1and wherein said removing moisture comprises removing moisture in anamount equal to approximately 12% of said weight of said agriculturalproduce.
 4. A method according to claim 1 and wherein said removingmoisture comprises transporting said agricultural produce through amoisture removal chamber including at least one of a controlledtemperature chamber, a controlled air flow chamber, a controlledtemperature and air flow chamber, a microwave chamber, an infraredchamber, a convection chamber, a chamber having fluidized bed technologyand a chamber having vacuum drying technology.
 5. A method according toclaim 1 and also comprising, prior to said freezing, pre-cooling saidagricultural produce to a temperature between 0° C. and 5° C.
 6. Amethod according to claim 1 and wherein said freezing comprises freezingsaid agricultural produce to a temperature between −40° C. and −35° C.by employing IQF freezing technology.
 7. A method according to claim 1and also comprising, following said freezing, adding liquid to saidagricultural produce and defrosting said agricultural produce in thepresence of said liquid.
 8. A method for preserving uncut freshagricultural produce comprising: non-manually handling said uncut freshagricultural produce; thereafter, removing moisture from said uncutfresh agricultural produce in an amount equal to between 5%-20% of theweight of said uncut fresh agricultural produce at a rate which does notexceed approximately 60×10⁻⁶ kg moisture/sec per area unit of saidproduce in meter²; and thereafter, freezing said uncut freshagricultural produce.
 9. A method according to claim 8 and wherein saidremoving moisture comprises removing moisture in an amount equal toapproximately 10%-14% of said weight of said agricultural produce.
 10. Amethod according to claim 8 and wherein said removing moisture comprisesremoving moisture in an amount equal to approximately 12% of said weightof said agricultural produce.
 11. A method according to claim 8 andwherein said removing moisture comprises transporting said agriculturalproduce through a moisture removal chamber including at least one of acontrolled temperature chamber, a controlled air flow chamber, acontrolled temperature and air flow chamber, a microwave chamber, aninfrared chamber, a convection chamber, a chamber having fluidized bedtechnology and a chamber having vacuum drying technology.
 12. A methodaccording to claim 8 and also comprising, prior to said freezing,pre-cooling said agricultural produce to a temperature between 0° C. and5° C.
 13. A method according to claim 8 and wherein said freezingcomprises freezing said agricultural produce to a temperature between−40° C. and −35° C. by employing IQF freezing technology.
 14. A methodaccording to claim 8 and also comprising, following said freezing,adding liquid to said agricultural produce and defrosting saidagricultural produce in the presence of said liquid.
 15. A method forpreserving fresh cut agricultural produce comprising: removing moisturefrom said fresh cut agricultural produce in an amount equal to between5%-20% of the weight of said fresh cut agricultural produce at a ratewhich does not exceed approximately 300×10⁻⁶ kg moisture/sec per areaunit of said produce in meter²; and thereafter, freezing said fresh cutagricultural produce.
 16. A method according to claim 15 and whereinsaid removing moisture comprises removing moisture in an amount equal toapproximately 10%-14% of said weight of said agricultural produce.
 17. Amethod according to claim 15 and wherein said removing moisturecomprises removing moisture in an amount equal to approximately 12% ofsaid weight of said agricultural produce.
 18. A method according toclaim 15 and wherein said removing moisture comprises transporting saidagricultural produce through a moisture removal chamber including atleast one of a controlled temperature chamber, a controlled air flowchamber, a controlled temperature and air flow chamber, a microwavechamber, an infrared chamber, a convection chamber, a chamber havingfluidized bed technology and a chamber having vacuum drying technology.19. A method according to claim 15 and also comprising, prior to saidfreezing, pre-cooling said agricultural produce to a temperature between0° C. and 5° C.
 20. A method according to claim 15 and wherein saidfreezing comprises freezing said agricultural produce to a temperaturebetween −40° C. and −35° C. by employing IQF freezing technology.
 21. Amethod according to claim 15 and also comprising, following saidfreezing, adding liquid to said agricultural produce and defrosting saidagricultural produce in the presence of said liquid.
 22. Apparatus forpreserving manually handled uncut fresh agricultural produce comprising:a chamber operative to remove moisture from said manually handled uncutfresh agricultural produce in an amount equal to between 5%-20% of theweight of said manually handled uncut fresh agricultural produce at arate which does not exceed approximately 30×10⁻⁶ kg moisture/sec perarea unit of said produce in meter²; and at least one freezing deviceoperative to freeze said manually handled uncut fresh agriculturalproduce.
 23. Apparatus for preserving non-manually handled uncut freshagricultural produce comprising: a chamber operative to remove moisturefrom said non-manually handled uncut fresh agricultural produce in anamount equal to between 5%-20% of the weight of said non-manuallyhandled uncut fresh agricultural produce at a rate which does not exceedapproximately 60×10⁻⁶ kg moisture/sec per area unit of said produce inmeter²; and at least one freezing device operative to freeze saidnon-manually handled uncut fresh agricultural produce.
 24. Apparatus forpreserving fresh cut agricultural produce comprising: a chamberoperative to remove moisture from said fresh cut agricultural produce inan amount equal to between 5%-20% of the weight of said fresh cutagricultural produce at a rate which does not exceed approximately300×10⁻⁶ kg moisture/sec per area unit of said produce in meter²; and atleast one freezing device operative to freeze said fresh cutagricultural produce.
 25. A method of storing agricultural producecomprising: removing moisture from said agricultural produce in anamount equal to between 5%-20% of the weight of said agriculturalproduce; thereafter, freezing said agricultural produce; and thereafter,adding liquid to said agricultural produce and defrosting saidagricultural produce in the presence of said liquid.
 26. Apparatus forstoring agricultural produce comprising: a container for storing saidfrozen agricultural produce and having a container opening; a sealformed over said opening of said container; a cap removably attached tosaid container and disposed over said seal, said cap being apertured topermit liquid, but not said produce, to pass therethrough and out ofsaid container.
 27. Apparatus according to claim 26 and wherein saidcontainer has indicated thereon a line indicating a desired level towhich said liquid should be added to said container prior to defrosting.28. A method for storing agricultural produce comprising: removingmoisture from said agricultural produce in an amount equal to between5%-20% of the weight of said agricultural produce; thereafter, freezingsaid agricultural produce and storing it in a container for storingfrozen agricultural produce and having a container opening; sealing theopening of said container; storing said container containing saidagricultural produce under freezing conditions; unsealing the opening ofsaid container; supplying a liquid to said agricultural produce in saidcontainer; defrosting said agricultural produce in said container in thepresence of said liquid; removably attaching an apertured cap to saidcontainer and pouring out said liquid from said container through saidapertured cap, thereby permitting said liquid, but not said produce, topass out of said container.
 29. A method according to claim 28 andwherein different types of said agricultural produce are mixed together.30. A method according to claim 28 and wherein said defrosting comprisesdefrosting said agricultural produce at room temperature for a durationof approximately 3 to 5 minutes.
 31. A method according to claim 28 andwherein said defrosting comprises defrosting said agricultural producein a microwave oven for a duration of approximately 15 to 30 seconds.